The U.S. Government has a paid-up non-exclusive license in this invention, and may have other rights as stipulated in 35 USC S202(C).
1. Field of the Invention
This invention relates to the fields of protein biochemistry, protein sequences, drugs and therapeutics. More specifically, the present invention relates to peptides and antibodies useful for modulating neutrophil chemotaxis in the immune response and in wound healing.
2. Description of Related Art
An enzyme in blood (thrombin) plays an important role in the inflammatory process and in initiating early stages of wound healing (Carney 1992; Carney et al. 1992b) by stimulating a number of cellular events which increase vascular permeability and recruit inflammatory cells to the site of tissue injury. It activates platelets and stimulates proliferation of fibroblasts (Carney et al. 1978; Perez-Rodriguez et aL 1981), capillary endothelial cells (Belloni et al. 1992), epithelial cells (He et aL 1991), neuronal cells (Gurwitz and Cunningham 1988), monocytes (Bar-Shavit et aL 1986), and T cells (Naldini et al. 1993). Additionally, a thrombin-derived synthetic peptide, TRAP-508, accelerates wound healing and revascularization through mechanisms that mimic normal effects of thrombin on microvascular endothelial cells and the recruitment of inflammatory cells to the wound site in vivo (Carney et al. 1992a; Stiernberg et al. 1993). However, the mechanisms by which this enzyme and related synthetic peptides stimulate these cellular events are quite complex and not generally understood.
It is highly useful for research and clinical purposes to have available the biochemical factors which mediate the various mechanisms that regulate the wound healing and inflammation processes. Neutrophil cell chemotaxis initiated by thrombin is one such mechanism involved in the wound healing/inflammation response process about which more needs to be known.
What is known about these processes is that thrombin and thrombin peptides play a role in chemotactic recruitment of inflammatory cells, including neutrophils (a.k.a. polymorphonuclear leukocytes) to a wound site. Further, it is known that at the injury site, thrombin causes proteolytic cleavage and activation of a G-protein-linked Proteolytically Activated Receptor for Thrombin (PART) that is present on the surface of platelets and endothelial cells (Vu et al. 1991; Rasmussen et al. 1991; Zhong et al. 1992), which results in release of an N-terminal peptide of approximately 15-amino acids.
However, prior to the present invention, the fate of this N-terminal peptide cleavage fragment was not known, nor was there any known function or use for this peptide fragment. Tests on fibroblasts and other cells using the released N-terminal peptide had found no apparent activity of the released peptide Van Obberghen-Schilling and Pouyssegur 1993).